JP2000300085A - Greenhouse horticulture film - Google Patents

Abstract

(57) [Problem] To provide a film for greenhouse horticulture which has good properties such as anti-fogging property, anti-fog property and heat retaining property, but hardly adhere to each other even when produced by a production facility. A tubular film formed by an inflation method is provided with a slit portion along a longitudinal direction, and when the tubular film is opened from the slit portion and spread on a greenhouse, the outer skin of the tubular film is provided. Is an inner layer (A) located on the inner surface side of the facility gardening house, and an outer layer (C) in which the inner surface of the tubular film is located on the outer surface side of the facility gardening house
An ethylene-vinyl acetate copolymer (a) wherein the inner layer (A) of the tubular film has a vinyl acetate content of 2 to 10% by weight. For horticultural use, wherein the outer layer (C) of the cylindrical film comprises a composition mainly composed of the ethylene-α-olefin copolymer (c1) or the ethylene homopolymer (c2). the film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a greenhouse horticulture film for use in greenhouse horticulture houses and the like. More specifically, the present invention relates to a greenhouse horticultural film having excellent anti-blocking properties and excellent de-laying and spreading workability.

[0002]

2. Description of the Related Art Various plastic films are used as covering materials for greenhouse gardens and greenhouse tunnels. Typical examples thereof include a polyvinyl chloride film (hereinafter referred to as agricultural plastic), a polyethylene film (hereinafter referred to as agricultural plastic), an ethylene vinyl acetate copolymer film (hereinafter referred to as agricultural plastic). Can be mentioned. Above all, agriculture is most frequently used because of its excellent heat retention, transparency, toughness, antifogging property, house adhesion and economic efficiency.

However, agricultural plastics have the disadvantage that additives contained in the film gradually ooze out on the film surface, causing stickiness on the film surface and deteriorating workability and dust resistance. ing. In addition, a problem that harmful gas is generated when incinerating and disposing of agricultural plastics is taken up, and a substitute for agricultural plastic that does not generate harmful gas is desired. On the other hand, agricultural poly and agricultural vinegar are superior to agricultural virgin in terms of workability, dust resistance and ease of disposal, but are inferior to agricultural virgin in heat retention, anti-fog properties, toughness, etc. Therefore, improvement has been desired.

[0004] In order to improve the heat retaining properties of these agricultural poly and agricultural vinegar, JP-A-60-104141 discloses a technique of adding a specific inorganic filler having an infrared absorbing property. In order to improve the anti-fogging property and toughness, Japanese Patent Application Laid-Open No. 58-90960 discloses that in a multilayer film, an outer layer (a layer in contact with the atmosphere inside a house or a tunnel) is a linear low-density polyethylene, Ethylene-vinyl acetate copolymer or olefin-vinyl alcohol copolymer,
An agricultural laminated film using a linear low-density polyethylene or an ethylene-vinyl acetate copolymer for an inner layer (a layer in contact with the atmosphere inside a house or a tunnel) has been proposed.

In general, when a multilayer film is produced by an inflation method, a thermoplastic resin composition as a material is put into several heated extruders, kneaded by screws of each extruder, and then formed into a circular shape. The layers are stacked inside a heated circular die having a lip and extruded above the lip. The one thus extruded into a cylindrical shape is called a bubble. The bubble is cooled by blowing air from the outer periphery of the bubble using an air ring, and then double-folded or gusset-folded as shown in FIGS. 1 and 2 and taken up by a pair of pressure rolls. In addition, a slit portion is provided along the length direction of the tubular film so that the tubular film that has been pressed can be opened (hereinafter, referred to as “opening”) and extended to a facility gardening house. The slit portion may be provided using a slitter before being wound on a paper tube or the like, but when a roll of a tubular film wound on a paper tube or the like is fed out and cut to fit the dimensions of the greenhouse. May be provided.

For example, in a multilayer film comprising an inner layer, an intermediate layer and an outer layer, when forming a multilayer film using an ethylene-vinyl acetate copolymer for each of the inner layer, the intermediate layer and the outer layer, the extrusion temperature and the die A processing temperature such as a temperature is carried out at about 150 to 170 ° C., but a linear low-density polyethylene such as ethylene-produced as disclosed in JP-A-58-90960 is used.
When an α-olefin copolymer is used, 170 to 200 ° C.
Processing temperature is required.

Further, when a wide blown film which can be coated on an actual greenhouse is produced by a large-sized machine, in addition to the above-mentioned processing temperature, the shape of the die itself from which the resin is extruded is large. There is a problem that the amount of heat transfer increases, the cooling efficiency is poor, and the films come into close contact with each other and cannot be easily peeled off (hereinafter referred to as "blocking"), and the crimped cylindrical film does not easily open from the slit. Was.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a film having good properties such as anti-fogging property, anti-fog property, and heat retaining property, and film portions are hardly adhered to each other even when produced by a production facility. It is an object of the present invention to provide a greenhouse horticultural film formed by an inflation method, which can be easily opened from the ground.

[0009]

Means for Solving the Problems The inventors of the present invention have identified the above-mentioned problems in the prior art, namely, the outer layer (house outer surface side) containing an ethylene-α-olefin copolymer as a main component and the ethylene-vinyl acetate copolymer. As a result of intensive studies to improve the blocking that occurs when an industrial horticultural film having an inner layer mainly composed of coalesced (the inner side of the house) is actually produced, the outer skin of the tubular film is used as the inner layer, It has been found that a film that is difficult to block can be produced by using the endothelium as the outer layer, and the present invention has been completed based on this finding.

The present invention has the following configuration. (1) The tubular film formed by the inflation method is provided with a slit portion along the length direction, and when the tubular film is opened from the slit portion and spread on a greenhouse, the outer skin of the tubular film is removed. A facility horticulture film comprising an inner layer (A) located on the inner surface side of the facility horticulture house, and an inner layer of the tubular film comprising two or more layers which is an outer layer (C) located on the outer surface side of the facility horticulture house. The inner layer (A) of the tubular film is composed of a composition mainly containing an ethylene-vinyl acetate copolymer (a) having a vinyl acetate content of 2 to 10% by weight. C) is an ethylene-α-olefin copolymer (c)
1) Or a greenhouse horticultural film comprising a composition mainly composed of an ethylene homopolymer (c2). (2) Density of 0.89 or higher where ethylene-α-olefin copolymer (c1), which is the main component of the composition constituting the outer layer (C) that is the inner layer of the tubular film, is polymerized using a single-site catalyst. The facility horticultural film according to the above (1), which is a 0.94 g / cm ³ ethylene-α-olefin copolymer. (3) One or more inorganic fillers are added to the composition constituting the outer layer (C), which is the inner layer of the tubular film, and the addition ratio X weight% and the BET specific surface area S (m
² / g), wherein the film for greenhouse horticulture according to the above (1) or (2), satisfies the relationship of 1 / S ≦ X ≦ 100 / S.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the greenhouse horticulture film of the present invention will be described in detail. The film for greenhouse horticulture of the present invention is any one or two of ethylene-vinyl acetate copolymer (a), ethylene-α-olefin copolymer (c1), ethylene homopolymer (c2) and inorganic filler.
It is a multilayer film of two or more layers composed of a composition containing at least one species. In the present invention, the “main component” of the composition refers to a component contained in the composition in an amount of 50% by weight or more.

[Ethylene-vinyl acetate copolymer] In the film for greenhouse horticulture of the present invention, the ethylene-vinyl acetate copolymer (a) used in the composition constituting the inner layer A, which is the outer skin of the tubular film, is ethylene. Is a copolymer of ethylene and vinyl acetate, and is produced by copolymerizing ethylene and vinyl acetate by a known high-pressure radical polymerization process. JIS K7 of the ethylene-vinyl acetate copolymer (a)
Melt flow rate (hereinafter M
FR) is 0.1 to 10 g / 10 min, preferably 0.5 to 5 g / 10 min. If the MFR is less than 0.1 g / 10 min, the moldability of the film, particularly the extrusion processability and high-speed stretchability, will be poor, and if it exceeds 10 g / 10 min, the moldability of the film, especially the stability of the bubbles in inflation molding, will be poor. Tend.

The ethylene-vinyl acetate copolymer (a)
Has a vinyl acetate content of 2 to 10% by weight,
If it is less than the desired value, the desired antifogging property, in particular, the effect of expression at low temperatures cannot be obtained, and the antifogging durability will also be reduced. On the other hand, when the content exceeds 10% by weight, it is not preferable because the films adhere to each other, or when the film is left outdoors, heat is stored by sunlight and the films fuse together.

[Ethylene-α-olefin copolymer] In the greenhouse horticulture film of the present invention, an ethylene-α-olefin copolymer (c1) used in the composition constituting the outer layer C which is the inner skin of the tubular film Is a random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and is polymerized using a multi-site catalyst such as a Ziegler catalyst or a single-site catalyst such as a metallocene catalyst;
Its density (d _c1 ) is between 0.87 and 0.96 g / cm ³ .

Among them, when the ethylene-α-olefin copolymer (c1) used in the composition constituting the outer layer C is polymerized using a multi-site catalyst, the density (d _c1 ) is 0.91. Those having a size of 0.94 g / cm ³ are preferably used. If the density (d _c1 ) is less than 0.91 g / cm ³ , the resulting film may be sticky or sticky, and if the density (d _c1 ) exceeds 0.94 g / cm ³ In this case, the flexibility of the film is reduced, so that the workability at the time of spreading and collection is reduced.

When the ethylene-α-olefin copolymer (c1) used in the composition constituting the outer layer C is polymerized using a single-site catalyst, the density (d _c1 )
Is preferably 0.89 to 0.94 g / cm ³ . When the density (d _c1 ) is less than 0.89 g / cm ³ , the melting point of the ethylene-α-olefin copolymer (c1) is lowered, and the films obtained by using the same are melted by irradiation with sunlight. Easy to wear. The density is 0.94 g / cm ³
If the ratio exceeds the above range, the flexibility of the film will be reduced, and the workability at the time of stretching and collection will be reduced.

In particular, the ethylene-α-olefin copolymer polymerized using a single-site catalyst has a narrower molecular weight distribution and a smaller α-molecular weight than a conventional multi-site catalyst such as a Ziegler-Natta catalyst. -High content of olefin is also polymerized uniformly and has many tie molecules between lamellae.Therefore, low molecular weight component is small and excellent in blocking resistance, transparency, impact resistance and toughness. Since it has excellent characteristics, it is suitably used for the composition constituting the outer layer C.

The α-olefin having 3 to 20 carbon atoms includes propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene,
Dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like. The content of the α-olefin in the random copolymer is 1 to 45% by weight, preferably 2 to 35% by weight. It is.

As the single-site catalyst, a combination of a metallocene compound of a transition metal of Group IV or V of the periodic table, such as titanium, zirconium, hafnium, and vanadium, with an organic aluminum compound and / or an ionic compound is used.

Examples of the metallocene compound include those crosslinked with at least one cyclopentadienyl group, substituted cyclopentadienyl group, hydrocarbyl silicon, etc., and those in which the cyclopentadienyl group is crosslinked with oxygen, nitrogen and phosphorus atoms. Any known metallocene compound having a compound as a ligand can be used.

Specific examples of these metallocene compounds include dimethylsilyl (2,4-dimethylcyclopentadienyl) (3 ', 5'-dimethylcyclopentadienyl) zirconium dichloride, dimethylsilyl (2,4-dimethyl Silicon-bridged metallocene compounds such as cyclopentadienyl) (3 ', 5'-dimethylcyclopentadienyl) hafnium dichloride, ethylenebisindenylzirconium dichloride, ethylenebisindenylhafnium dichloride, ethylenebis (methylindenyl) zirconium Examples include indenyl crosslinked metallocene compounds such as dichloride and ethylenebis (methylindenyl) hafnium dichloride.

The organoaluminum compound used in combination with the metallocene compound is represented by the general formula-(Al
(R) O) _n- a linear or cyclic polymer (R is a hydrocarbon group having 1 to 10 carbon atoms, including those partially substituted with a halogen atom and / or an RO group. n is the degree of polymerization and is 5 or more, preferably 10 or more), and specific examples include methylalumoxane, ethylalumoxane, and isobutylethylalumoxane, wherein R is each a methyl, ethyl, or isobutyl group. Can be

Further, other organic aluminum compounds include trialkylaluminum, dialkylhalogenoaluminum, sesquialkylsesquihalogenoaluminum, trialkenylaluminum, dialkylhydroaluminum, and sesquialkylsesquihydroaluminum.

The ionic compound is represented by the general formula [Q] ^{m +} [Y] ^m- (m is an integer of 1 or more), wherein Q is a cation component of the ionic compound, And a cationium ion, a tropylium cation, an ammonium cation, an oxonium cation, a sulfonium cation, and a phosphonium cation. Y is an anionic component of an ionic compound, which is a component that reacts with a metallocene compound to form a stable anion, and includes an organic boron compound anion, an organic aluminum compound anion, an organic gallium compound anion, an organic phosphorus compound anion, and an organic compound. Arsenic compound anions,
Organic antimony compound anions and the like.

As a method for copolymerizing ethylene and an α-olefin using a single-site catalyst, a known polymerization method is used, and examples thereof include a gas phase polymerization method, a slurry polymerization method, and a solution polymerization method.

The number average molecular weight of the ethylene-α-olefin copolymer is in the range of 1 × 10 ^{4 to} 100 × 10 ⁴ , and the Q value which is the ratio of the weight average molecular weight to the number average molecular weight is 1.5. ３3.5. In addition, 190 ° C, 2.
MFR under load condition of 16 kgf is 0.2 to 20 g / 10
And the number of melting peaks by differential scanning calorimetry (DSC) may be two or more, but is preferably one in order to improve transparency and toughness.

[Ethylene homopolymer] In the present invention, the ethylene homopolymer (c2) used in the composition constituting the outer layer C, which is the inner skin of the tubular film, has a density (d _c2 ) of _0.1 .
Those having 91 to 0.94 g / cm ³ are preferably used. Density (d _c2) is 0.91 g / cm ³ less than the ethylene homopolymer hard to polymerization, it reduces the flexibility of the film obtained by using this if exceeding 0.94 g / cm ³ deployed or when recovering Workability at the time will be reduced. As the ethylene homopolymer (c2), a polymer obtained by polymerization using a known high-pressure radical method or the single-site catalyst is used. In particular, an ethylene homopolymer polymerized with a single-site catalyst is suitably used for the same reason as the ethylene-α-olefin copolymer.

The composition constituting the outer layer C, which is the inner skin of the tubular film, includes the above-mentioned ethylene-α-olefin copolymer, ethylene homopolymer, and further different types of ethylene-α.
-Two or more olefins or different kinds of ethylene homopolymers may be used in combination.

[Inorganic filler] The inorganic filler added to the outermost skin of the tubular film in the present invention includes:
Silicate compounds such as silicon oxide, magnesium silicate, aluminum silicate, calcium silicate, calcium aluminosilicate,
Aluminosilicate compounds such as sodium aluminosilicate and potassium aluminosilicate, alumina, sodium aluminate,
It is selected from the group consisting of aluminate compounds such as potassium aluminate and calcium aluminate, calcium carbonate, hydrotalcites represented by the following formula 1, and lithium / aluminum composite hydroxide salts represented by the following formulas 2 and 3. One or more inorganic fillers may be used.

[0030]

Embedded image [Al ₂ Li (OH) ₆ ] ₂ (A ⁿ⁻ ) · mH ₂ O—Formula 1 (where m represents a number of 3 or less)

[0031]

Embedded image [Al ₂ (Li _(1-x) · M ²⁺ _x ) (OH) ₆ ] ₂ · (Si _y O _{2y + 1} ² ) _{1 + x} · mH ₂ O-Formula 2 , M ²⁺ is a divalent metal, m is a number in the range of 0 ≦ m <5, x is a number in the range of 0 ≦ x <1, y is 2 ≦ y ≦ 4
Indicates a number in the range. )

[0032]

^{Embedded image} M 2 ⁺ _{1 -x} Al _x (OH) ₂ (A ⁿ⁻ ) _{x / 2} .mH ₂ O-Formula 3 (where M ²⁺ is Mg ²⁺ , Ca ²⁺ , and Zn ^{2 +} represents at least one divalent metal ion selected from among, a ^n-
Is an n-valent anion, x and m are the following conditions, 0 <x <
0.5, 0 ≦ m ≦ 2. )

In the present invention, the addition rate X weight% of the inorganic filler added to the composition constituting the inner layer A, which is the outer skin of the tubular film, and the BET specific surface area S of the inorganic filler measured according to JIS Z 8830 (M ² / g)
It is desirable to satisfy the relationship of 1 / S ≦ X ≦ 100 / S, and when the addition ratio X is less than 1 / S, the films are easily blocked with each other, and the addition ratio X is 100 / S.
If it is larger than S, transparency and mechanical strength are undesirably reduced.

The composition constituting not only the inner skin (outer layer C) of the tubular film but also the outer skin (inner layer A) and other layers may contain one or more members selected from the above-mentioned inorganic fillers alone or in combination. It may be added in combination.

[Other Components] In the present invention, various substances may be added as long as the object of the present invention is not impaired. A known thermoplastic resin such as a high-pressure low-density polyethylene can be added to the composition constituting each layer in order to improve the film forming processability. In addition, in order to improve flexibility, an elastic copolymer such as an ethylene-diene elastic copolymer, an ethylene-propylene elastic copolymer, or a styrene-butadiene elastic copolymer polymerized with a single-site catalyst or a known multi-site catalyst is used. A polymer may be added. In addition, known hindered amine weathering agents, ultraviolet absorbers, antifog agents (fluorinated surfactants), antistatic agents, lubricants, antioxidants, heat stabilizers, antibacterial agents, which are commonly used in agricultural films, Dyes and colorants can be blended.

The thickness of the greenhouse horticultural film of the present invention varies depending on the place where the film is used, the service life thereof, and the like.
Those having a thickness of about 05 to 0.3 mm are preferably used. Although the thickness of the inner layer and the thickness of the outer layer are not particularly limited,
A range of 5 to 50% of the total layer thickness is preferably used.

The film for greenhouse horticulture of the present invention can be produced by a known inflation method, and may be subjected to corona discharge treatment after production for the purpose of improving the effect of exhibiting anti-fogging properties. In addition, a multilayer film having a three-layer structure in which an intermediate layer B was provided between an inner layer A and an outer layer C, an intermediate layer D provided with heat retention, an intermediate layer E for improving antifogging properties, and a recycled material were put therein. It may be a multilayer film having a structure of four or more layers in which an intermediate layer F and the like are laminated. Further, an antifogging coating agent or the like may be applied and dried to form a coating film on the surface.

The greenhouse horticultural film may be transparent, satin-finished, or semi-peared, and may be used for mulching other than for covering agricultural houses (greenhouses) and tunnels.
It may be used for purposes such as bagging.

[0039]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In addition, evaluation of the film for greenhouse horticulture in an Example and a comparative example was implemented as follows.

1) Blocking resistance: A set of two samples each having a width of 20 mm and a length of 120 mm, and in which the inner surfaces of the cylindrical films overlap each other, are taken from each of the cylindrical film samples wound double around a paper tube. And 50 from both ends in the length direction
mm and the area of 20 mm x 20 mm is overlapped. A 1 kg load was applied to a 20 mm × 20 mm overlapping portion of the sample, and the sample was allowed to stand for 24 hours in an environment of 23 ° C. and 50% RH. Thereafter, a tensile test was performed to measure the blocking resistance. The larger the number, the more closely the film adheres, and the lower the workability at the time of secondary processing of the film and at the time of stretching. 2) Opening workability: The workability when unfolding the double-folded sheet into a single sheet by opening the double-folded state was evaluated according to the following criteria. Good: A level at which a double-layered film can be opened with almost no resistance. Possible: Films are blocking (adhering),
There is resistance to open, and whitening due to some deformation of the film. Impossible: Blocking between the films was severe, and if the film was forcibly opened, the film would be deformed, causing whitening or tearing.

The thermoplastic resin used for each layer is shown below. Yumerit (trademark) 1520F manufactured by Ube Industries, Ltd. ・ Thinkupulsite catalyst-based ethylene-α-olefin copolymer resin (S-LLDPE) ・ MFR: 2.0 g / 10 min., Density: 0.913 g / cm ³ Yumerit (trademark) 0540F Manufactured by Ube Industries, Ltd. ・ Think Persite catalytic ethylene-α-olefin copolymer resin (S-LLDPE) ・ MFR: 4.0 g / 10 min., Density: 0.904 g / cm ³ NUC3270 Nippon Unicar Co., Ltd. ・Ethylene vinyl acetate copolymer resin (vinyl acetate content 7.5%) (EV
A) ・ MFR: 2.3 g / 10 min., Density: 0.925 g / cm ³ , tensile modulus;
1300 kgf / cm ² Ultracene (trademark) 630 manufactured by Tosoh Corporation ・ Ethylene divinyl acetate copolymer resin (vinyl acetate content 15%) (EVA) ・ MFR: 1.5 g / 10 min., Density: 0.936 g / cm ³ , Tensile modulus;
570 kgf / cm ² Nipolon-L (registered trademark) FR151A manufactured by Tosoh Corporation ・ Multi-site catalytic ethylene-α-olefin copolymer resin (M-LLDPE) ・ MFR: 0.9 g / 10 min., Density: 0.924 g / cm ³ , tensile modulus;
2800kgf / cm ² UBE polyethylene R500 manufactured by Ube Industries, Ltd. ・ High pressure method low density polyethylene (LDPE) ・ MFR 0.5g / 10min., Density 0.922g / cm ³

The characteristics of each of the above thermoplastic resins were measured under the following conditions. 1) MFR: 190 ° C. according to JIS K7210,
It was measured under the condition of 2.16 kgf. 2) Density: measured according to JIS K7112.

Examples 1 to 3 and Comparative Examples 1 to 2 Using a large-sized three-layer blown film production machine having a 75 mmφ extruder and one 90 mmφ extruder, a molding temperature of 180 ° C. and a thickness of 0.1 mm were used. A multilayer film having a forming width of 3 m was formed. Tables 1 and 2 show the composition examples and evaluation results of each multilayer film. The endothelium, intermediate layer,
The outer skin refers to an inner skin, an intermediate layer, and an outer skin of a cylindrical film laminated in three layers.

Examples 4-5, Comparative Examples 3-4 Using a three-layer, three-layer blown film forming tester having three 50 mmφ extruders at a molding temperature of 180 ° C.
A multilayer film having a thickness of 0.1 mm and a width of 0.6 m was formed. Tables 1 and 2 show the composition examples and evaluation results of each multilayer film.

Examples of the composition of each multilayer film are shown in Tables 1-2.
In addition to the contents of the above, the outer layer C which is the inner
0.5% by weight of a hindered amine-based weathering agent, 0.05% by weight of an ultraviolet absorber, 0.1% by weight of a phenol-based stabilizer, and 0.1% by weight of a phosphorus-based stabilizer. 0.5% by weight of weathering agent, 0.
05% by weight, fluorine-based surfactant 0.2% by weight, phenol-based stabilizer 0.1% by weight, phosphorus-based stabilizer 0.1% by weight
In the inner layer A, which is the outer skin of the tubular film, 0.5% by weight of a hindered amine-based weathering agent and 0.5% of an ultraviolet absorber.
05% by weight, fluorine-based surfactant 0.2% by weight, phenol-based stabilizer 0.1% by weight, phosphorus-based stabilizer 0.1% by weight
Was added.

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

As described above, the horticultural film of the present invention has the advantage that the film is hardly blocked even in production by a large-sized machine having a reduced cooling efficiency, and is excellent in workability when opening a double-folded or gusset-folded film. It can be suitably used as a covering material for gardening houses and tunnels.

[Brief description of the drawings]

FIG. 1 shows double folding of a blown film.

FIG. 2 shows a gusset fold of a blown film.

FIG. 3 is an example of a sectional view of a greenhouse horticulture film according to the present invention.

[Explanation of symbols]

1 ... Outer layer of the inner surface of the tubular film on the outer surface side of the house. 2 ... An intermediate layer located between the inner skin and the outer skin of the tubular film. 3. Inner layer on the inner surface side of the house, which is the outer skin of the tubular film. 4 An example of double folding. 5 An example of gusset folding. 6... Slits provided along the length of the tubular film.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B29C 55/28 B29C 55/28 B29K 55:00 503: 04 B29L 7:00 F term (Reference) 2B024 DB01 DB07 FB01 2B029 EB03 EC02 EC16 EC18 EC20 4F100 AA01B AA01H AK04B AK63B AK68A AK68C AK68G BA02 BA03 BA10A BA10B BA15 CA23B EH20 EJ38 GB01 JA20B JA20H JD20 JJ02 JL00 JL00 A03A01 A30

Claims (3)

[Claims] 1. A tubular film formed by an inflation method is provided with a slit portion along a length direction, and when the tubular film is opened from the slit portion and spread on a facility gardening house, the tubular film is formed. The outer layer is an inner layer (A) located on the inner side of the greenhouse, and the inner layer of the tubular film is an outer layer (C) located on the outer side of the greenhouse.
An ethylene-vinyl acetate copolymer (a) wherein the inner layer (A) of the tubular film has a vinyl acetate content of 2 to 10% by weight. For horticultural use, wherein the outer layer (C) of the cylindrical film comprises a composition mainly composed of the ethylene-α-olefin copolymer (c1) or the ethylene homopolymer (c2). the film. 2. The density of the ethylene-α-olefin copolymer (c1), which is a main component of the composition constituting the outer layer (C) constituting the inner skin of the cylindrical film, is polymerized using a single-site catalyst. The greenhouse horticultural film according to claim 1, which is an ethylene-α-olefin copolymer having a weight ratio of 89 to 0.94 g / cm ³ . 3. A composition for forming an outer layer (C) which is an inner layer of a tubular film, wherein one or more inorganic fillers are added,
The greenhouse horticultural film according to claim 1 or 2, wherein the addition ratio X wt% and the BET specific surface area S (m ² / g) of the inorganic filler satisfy a relationship of 1 / S ≦ X ≦ 100 / S.